Ken Thompson

Bio: Ken Thompson is an academic researcher from Bell Labs. The author has contributed to research in topics: Unix & Unix filesystem. The author has an hindex of 27, co-authored 50 publications receiving 6752 citations. Previous affiliations of Ken Thompson include Alcatel-Lucent & Antec.

The UNIX time-sharing system

Abstract: UNIX is a general-purpose, multi-user, interactive operating system for the Digital Equipment Corporation PDP-11/40 and 11/45 computers. It offers a number of features seldom found even in a larger operating systems, including: (1) a hierarchical file system incorporating demountable volumes; (2) compatible file, device, and inter-process I/O; (3) the ability to initiate asynchronous processes; (4) system command language selectable on a per-user basis; and (5) over 100 subsystems including a dozen languages. This paper discusses the nature and implementation of the file system and of the user command interface.

Password security: a case history

Abstract: This paper describes the history of the design of the password security scheme on a remotely accessed time-sharing system. The present design was the result of countering observed attempts to penetrate the system. The result is a compromise between extreme security and ease of use.

Programming Techniques: Regular expression search algorithm

Abstract: A method for locating specific character strings embedded in character text is described and an implementation of this method in the form of a compiler is discussed. The compiler accepts a regular expression as source language and produces an IBM 7094 program as object language. The object program then accepts the text to be searched as input and produces a signal every time an embedded string in the text matches the given regular expression. Examples, problems, and solutions are also presented.

Reflections on trusting trust

Abstract: To what extent should one trust a statement that a program is free of Trojan horses? Perhaps it is more important to trust the people who wrote the software.

Plan 9 from Bell Labs

Abstract: By the mid 1980 s, the trend in computing was away from large centralized time-shared computers towards networks of smaller, personal machines, typically UNIX worksta­ tions . People had grown weary of overloaded, bureaucratic timesharing machines and were eager to move to small, self-maintained systems, even if that meant a net loss in computing power. As microcomputers became faster, even that loss was recovered, and this style of computing remains popular today.

Handbook of Applied Cryptography

Abstract: From the Publisher: A valuable reference for the novice as well as for the expert who needs a wider scope of coverage within the area of cryptography, this book provides easy and rapid access of information and includes more than 200 algorithms and protocols; more than 200 tables and figures; more than 1,000 numbered definitions, facts, examples, notes, and remarks; and over 1,250 significant references, including brief comments on each paper.

The Hadoop Distributed File System

Abstract: The Hadoop Distributed File System (HDFS) is designed to store very large data sets reliably, and to stream those data sets at high bandwidth to user applications. In a large cluster, thousands of servers both host directly attached storage and execute user application tasks. By distributing storage and computation across many servers, the resource can grow with demand while remaining economical at every size. We describe the architecture of HDFS and report on experience using HDFS to manage 25 petabytes of enterprise data at Yahoo!.

The model checker SPIN

Abstract: SPIN is an efficient verification system for models of distributed software systems. It has been used to detect design errors in applications ranging from high-level descriptions of distributed algorithms to detailed code for controlling telephone exchanges. The paper gives an overview of the design and structure of the verifier, reviews its theoretical foundation, and gives an overview of significant practical applications.

Efficient string matching: an aid to bibliographic search

Abstract: This paper describes a simple, efficient algorithm to locate all occurrences of any of a finite number of keywords in a string of text. The algorithm consists of constructing a finite state pattern matching machine from the keywords and then using the pattern matching machine to process the text string in a single pass. Construction of the pattern matching machine takes time proportional to the sum of the lengths of the keywords. The number of state transitions made by the pattern matching machine in processing the text string is independent of the number of keywords. The algorithm has been used to improve the speed of a library bibliographic search program by a factor of 5 to 10.

The SPIN Model Checker: Primer and Reference Manual

Abstract: The SPIN Model Checker is used for both teaching software verification techniques, and for validating large scale applications. The growing number of users has created a need for a more comprehensive user guide and a standard reference manual that describes the most recent version of the tool. This book fills that need. SPIN is used in over 40 countries. The offical SPIN web site, spinroot.com receives between 2500 and 3000 hits per day. It has been estimated that up to three-quarters of the $400 billion spent annually to hire programmers in the United States is ultimately spent on debugging